Method for controlling a ship propulsion system comprising a surface propeller

Abstract

A method for controlling a ship propulsion system including a surface propeller, in which the desired capacity is interpreted as the target rotational value, the rotational speed control deviation is calculated from the desired rotational value and the actual rotational value of the internal combustion engine and an injection quantity for the rotational control of the internal combustion engine is determined using the rotational speed control deviation on a rotational speed controller. The trim position of the surface propeller is controlled by an arrangement controller in accordance with the capacity reserve of the internal combustion engine and the actual trim position and the effective rotational speed, the trim position being determined from the rotational speed control deviation.

The invention claimed is: 
     
       1. A method for automatically controlling a marine propulsion system with an internal combustion engine and a surface-piercing propeller, comprising the steps of: considering a desired power to be a set rotational speed (nSL); computing a rotational speed control deviation (dn) from the set rotational speed (nSL) and an actual rotational speed (nIST) of the internal combustion engine in a processor; determining an injection quantity (qV) in the processor for automatic rotational speed control of the internal combustion engine by a rotational speed controller from the rotational speed control deviation (dn); computing an effective rotational from rotational speed deviation (dn) in the processor using a step function engine map to provide a robust effective rotational speed; and con troll trim position (POS) of the surface-piercing propeller with a system controller in response to signals from the processor as a function of a power reserve (PRES) of the internal combustion engine, of an actual trim position (POS(IST)), and of the effective rotational speed (nEFF) that is determined from the rotational speed control deviation (dn), the trim position being adjusted by an actuator by only adjusting a shaft that drives the surface-piercing propeller in response to signals from the system controller. 
     
     
       2. The method in accordance with  claim 1 , wherein the effective rotational speed (nEFF) is computed by the engine map from the rotational speed control deviation (dn) and another input variable (E). 
     
     
       3. The method in accordance with  claim 2 , wherein the another input variable is a charge pressure of an exhaust gas turbocharger. 
     
     
       4. The method in accordance with  claim 2 , wherein a first pitch angle (Phi 1 ) is determined from the effective rotational speed (nEFF) by a trim preassignment unit with several selectable additional engine maps (KF 1 , KF 2 , KF 3 ). 
     
     
       5. The method in accordance with  claim 4 , wherein one of the selectable engine maps (KF 1 , KF 2 , KF 3 ) is selected as a function of a number of coupled shafts and a thrust direction signal (SRI) of a transmission. 
     
     
       6. The method in accordance with  claim 4 , wherein a second pitch angle (Phi 2 ) and a first pitch rate (VSR 1 ) are computed by a load control unit as a function of the first pitch angle (Phi 1 ), the power reserve (PRES), and the actual trim position (POS(IST)) of the surface-piercing propeller. 
     
     
       7. The method in accordance with  claim 6 , wherein, when the load control unit is in an activated state, the first pitch rate (VSR 1 ) and the second pitch angle (Phi 2 ) are computed by further engine maps as a function of the power reserve (PRES) or, alternatively, are set at a constant value. 
     
     
       8. The method in accordance with  claim 7 , wherein, when the load control unit is in the activated state, the first pitch rate (VSR 1 ) is set to zero if the value of the power reserve (PRES) lies within a dead band (GW 1 , GW 2 ). 
     
     
       9. The method in accordance with  claim 6 , wherein, when the load control unit is deactivated, the second pitch angle (Phi 2 ) equals the first pitch angle (Phi 1 ). 
     
     
       10. The method in accordance with  claim 6 , including computing a position control deviation (dPOS) from the second pitch angle (Phi 2 ) and the actual trim position (POS(IST)), and determining a second pitch rate (VSR 2 ) by a trim controller from the position control deviation (dPOS). 
     
     
       11. The method in accordance with  claim 10 , including setting either the first pitch rate (VSR 1 ) or the second pitch rate (VSR 2 ) as controlling for a control signal (STS) for determining the trim position (POS) of the surface-piercing propeller.